<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>登录系统</title>
    <style>
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Arial, sans-serif;
        }

        .container {
            width: 100vw;
            height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            position: relative;
            overflow: hidden;
            background-color: rgba(255, 182, 193, 0.1); /* 淡粉色背景 */
        }

        /* 修改后的GIF背景样式 */
        .login-bg {
            position: absolute;
            top: 40px;
            left: 40px;
            z-index: -1;
            opacity: 0.1;
            animation: rotate 20s linear infinite;
            width: 400px;    /* 增大到400px */
            height: 400px;
        }

        @keyframes rotate {
            from { transform: rotate(0deg); }
            to { transform: rotate(360deg); }
        }

        .login-form {
            width: 100%;
            max-width: 400px;
            background-color: rgba(255, 192, 203, 0.9); /* 粉色背景 */
            padding: 2rem;
            border-radius: 1rem;
            box-shadow: 0 12px 24px rgba(255, 105, 180, 0.2); /* 更柔和的粉色阴影 */
        }

        .form-title {
            text-align: center;
            color: white;
            margin-bottom: 1.5rem;
            font-size: 1.8rem; /* 增大标题字体 */
        }

        h1.form-title::after {
            content: "";
            position: absolute;
            width: 100%;
            height: 4px; /* 加粗装饰线 */
            background: linear-gradient(45deg, #fff, rgba(255,255,255,0));
            bottom: -30px;
            left: 0;
            animation: shine 1.5s infinite;
        }

        @keyframes shine {
            from { left: -100%; }
            to { left: 100%; }
        }

        /* 按钮样式优化 */
        #denglu {
            background-color: #ff69b4;
            color: white;
            font-size: 1.1rem;
        }

        #denglu:hover {
            background-color: #ff459e;
        }

        #zhuce {
            background-color: #ffe4e1;
            color: #ff69b4;
            font-size: 0.9rem;
        }

        #zhuce:hover {
            background-color: #ffb6c1;
        }

        /* 响应式调整 */
        @media (max-width: 768px) {
            .login-bg {
                width: 300px;
                height: 300px;
                top: 20px;
                left: 20px;
            }
            
            .form-title {
                font-size: 1.5rem;
            }
        }
    </style>
</head>
<body>
    <div class="container">
        <img src="https://q0.itc.cn/q_70/images03/20241220/e9f35e2555644895a714f14df31b9ed1.gif" 
             alt="Loading animation" 
             class="login-bg; color: transparent;"
             >
        
        <form class="login-form" action="#">
            <h1 class="form-title">欢迎使用某某系统</h1>
            <hr class="form-divider">
            
            <div class="form-group">
                <label for="username">用户名：</label>
                <input type="text" id="username" required>
            </div>

            <div class="form-group">
                <label for="password">密码：</label>
                <input type="password" id="password" required>
            </div>

            <div class="form-actions">
                <input type="submit" id="denglu" value="立即登录">
                <input type="reset" id="zhuce" value="注册新账号">
            </div>
        </form>
    </div>
</body>
</html>